WO2006064805A1

WO2006064805A1 - Electric treating method for exhaust gas of diesel engine and its device

Info

Publication number: WO2006064805A1
Application number: PCT/JP2005/022881
Authority: WO
Inventors: Munekatsu Furugen
Original assignee: Munekatsu Furugen
Priority date: 2004-12-17
Filing date: 2005-12-13
Publication date: 2006-06-22
Also published as: EP1837489B9; CN101111667A; KR101406649B1; EP1837489B1; JPWO2006064805A1; EP1837489A4; JP4931602B2; EP1837489A1; ATE548546T1; CN101111667B; KR20070100940A

Abstract

[PROBLEMS] To provide an exhaust gas treating technology of diesel engines capable of removing PM in exhaust gas of diesel engines with high efficiency and capable of exhibiting stabilized performance over a long term. [MEANS FOR SOLVING PROBLEMS] A discharging/charging section comprising a corona discharging section and a charging section is disposed on the upstream side of an exhaust gas passage in order to charge granular substances principally comprising carbon with corona discharged electrons, and then the charged granular substances are collected at a collecting section arranged on the exhaust gas passage.

Description

Specification

TECHNICAL FIELD OF THE INVENTION Technical Field

[0001] The present invention relates to an exhaust gas treatment technology for removing and purifying particulate matter (Particulate Matter: hereinafter referred to as "PM") mainly composed of carbon contained in exhaust gas of a diesel engine and harmful gas, More specifically, the present invention relates to an electric processing technology for exhaust gas of a diesel engine using corona discharge.

Background art

[0002] As is well known, PM contained in exhaust gas of a diesel engine not only causes air pollution but is also extremely harmful to the human body, so purification of the exhaust gas is extremely important. For this reason, improvements in diesel engine combustion methods, the use of various filters, or methods of electrical treatment using corona discharge have been proposed.

[0003] However, simply by improving the combustion system, it is difficult to drastically reduce PM because various operations such as cold start of the diesel engine, climbing, and overloading are performed. In addition, for example, the method of collecting PM with a ceramic filter or the like collects PM through fine holes or gaps, so when a certain amount of PM is collected, the pressure loss (venting resistance) of the exhaust gas increases rapidly. As a result, fuel consumption deteriorates and engine trouble occurs. Furthermore, the filter regeneration method in which the collected PM is combusted with a catalyst is not preferable because the degree of exhaust gas pressure loss increases due to catalyst deterioration due to catalyst use over a long period of time.

[0004] On the other hand, as a method of performing electrical treatment using corona discharge, as shown in FIG. 19, for example, corona discharge is caused around the needle tip 121a to charge PM123 in the exhaust gas. Needle electrode 121, a charged electrode 123 for collecting charged PM 123 a with electrostatic force, and a predetermined high DC voltage between the needle electrode 121 and the collecting electrode 124. 2. Description of the Related Art A diesel engine exhaust PM collection device (see Patent Document 1) having a high-voltage DC power supply 125 is known. A cylindrical body constituting one of the collection electrode pairs for collecting PM provided in the exhaust path; and an electrode body extending in the axial direction at the center of the cylindrical body and constituting the other of the collection electrode pairs; Forming an electrostatic field between the pair of collecting electrodes A high-voltage power supply unit for accumulating PM in the gas gas on the inner surface of the cylindrical body, and rotating relative to the cylindrical body along the inner surface of the cylindrical body to scrape the PM deposited on the inner surface of the cylindrical body. An exhaust gas purifying device having a dropping part (see Patent Document 2), a plurality of PM collecting electrodes each having an electric insulator layer and a catalyst layer, and each of the PM collecting electrodes, Many proposals have been made, such as an exhaust gas purification device (see Patent Document 3) having a discharge electrode provided with a plurality of needle-like electrodes protruding toward a layer.

Patent Document 1: Japanese Patent Laid-Open No. 9-112246

Patent Document 2: JP-A-6-173637

Patent Document 3: Japanese Patent Laid-Open No. 2003-269133

Disclosure of the invention

Problems to be solved by the invention

However, the conventional exhaust gas treatment technology of a diesel engine that performs electrical treatment using corona discharge has the following problems.

The exhaust PM collection device described in Patent Documents 1 and 2 employs a so-called single-stage electrostatic precipitator system. As a basic problem, the discharge voltage and the collection deflection voltage are at the same potential. For this reason, it is difficult to set both voltages to appropriate conditions, and it is necessary to increase the distance between the deflection electrode and the collection electrode in order to prevent the occurrence of sparks. For this reason, the exhaust PM collection device described in Patent Documents 1 and 2 has a drawback that the collection efficiency decreases because more particles pass through the collection section without being collected. In addition, in order to increase the collection efficiency, it is necessary to increase the capacity of the collection unit, which necessitates an increase in the size of the device and is inappropriate as an automobile part. Furthermore, the exhaust gas purifying device described in Patent Document 3 employs a so-called two-stage electrostatic precipitator method, and since there are no countermeasures against contamination of force needle electrodes, there are tens of thousands of discharge electrodes. When a high voltage of volt is applied, there is a disadvantage that the PM collection performance cannot be exhibited due to a decrease in electrical insulation due to contamination. In addition, the discharge electrode is inevitably contaminated by corrosive exhaust gas, and cannot maintain stable performance over a long period of time. Furthermore, in the case of a linear electrode, in the case of an automobile, there is a problem in strength that it is easy to cause a disconnection due to vibration or impact during driving. In other words, exhaust gas treatment that uses an electrical method using conventional corona discharge The means has a difficulty in practicality in which it is difficult to ensure high insulation of the discharge electrode.

[0006] The present invention eliminates the above-mentioned problems of the conventional diesel engine exhaust gas treatment technology using corona discharge, and can remove PM in the exhaust gas of a diesel engine with high efficiency and is stable over a long period of time. It is an object of the present invention to provide an electrical processing method and apparatus for exhaust gas of a diesel engine capable of exhibiting the above performance.

Means for solving the problem

[0007] An electric processing method for exhaust gas of a diesel engine according to the present invention is provided with a discharge charging unit comprising a corona discharge unit and a charging unit upstream of an exhaust gas passage, and the corona discharged electrons are exhausted. It is characterized in that the particulate matter mainly composed of carbon is charged and the charged particulate matter is collected by a collection part disposed in the exhaust gas passage.

[0008] Further, the exhaust gas electrical processing device for a diesel engine of the present invention corona discharge for charging electrons corona discharged upstream of the exhaust gas passage to particulate matter mainly composed of carbon in the exhaust gas. A discharge charging unit including a charging unit and a charging unit is provided, and a collecting unit that collects the charged particulate matter is disposed in the exhaust gas passage.

[0009] Further, the apparatus of the present invention is arranged such that the discharge-side tip of the electrode needle of the corona discharge portion is directed toward the downstream side of the exhaust gas flow, and corona electrons are discharged toward the downstream side. The pole needle is placed in a seal gas pipe made of an insulator, the seal gas pipe is made of alumina ceramic, and the protruding portion of the electrode needle from the end of the seal gas pipe is connected to the potential of the gas flow in the seal gas pipe. Positioning in the core, coating the electrode needle with a material having electrical insulation and corrosion resistance, using quartz glass, alumina or ceramic as the coating material for the electrode needle, and simply collecting the collecting portion. It should be a layered or multi-layered structure, and the collecting part is made up of a punching metal type collecting plate or a slit type collecting plate, and is defined as the total area of the apertures / the actual front area of the collecting part Ru An aperture ratio of 3 to 20%, a base plate made of a single plate that does not have an opening on the collection surface of the collection portion, and a lattice-shaped fin provided on the collection surface side of the base plate The electrode plate holding rod in the collector fixing portion of the single-layer plate structure or the multilayer plate structure is disposed in an insulating seal tube, and the rectifying member is entirely or partially disposed in the seal gas tube. Arrangement, before A dummy tube portion is provided on the tube wall opposite to the electrode needle tip side of the seal gas tube in parallel with the exhaust gas flow direction.

The seal gas pipe having the dummy pipe part has an inner diameter of the seal gas pipe D, a length of the dummy pipe part of the seal gas pipe part L1, and a length from the dummy pipe part to the tip part L2. In this case, it is preferable to satisfy the conditions of L1 / D> 1.5 and L2 / D> 0.5.

[0010] It is also acceptable that the apparatus of the present invention uses a combination of the exhaust gas electrical processing apparatus and a catalyst.

[0011] Further, as another electric processing apparatus for exhaust gas of a diesel engine according to the present invention, a cyclone dust collector is provided after the electric processing apparatus for exhaust gas. It is.

[0012] Further, in the electric processing apparatus for exhaust gas of a diesel engine equipped with a cyclone dust collector, the collection unit includes a base plate made of a single plate having no collection surface and a collection of the base plate. A plurality of collecting plates constituted by lattice-like fins provided on the surface side may be arranged so that a gap is formed between the inner wall of the apparatus body.

[0013] Furthermore, particle aggregation and coarsening means may be disposed in the subsequent stage of the exhaust gas electric processing apparatus and in the previous stage of the cyclone dust collector. As the particle aggregation coarsening means, a particle aggregation tube having a honeycomb structure, or a particle aggregation plate formed by arranging a plurality of punching metals or metal meshes at intervals can be used.

[0014] On the other hand, as a method for regenerating the collection plate of the exhaust gas electrical processing apparatus, an exhaust gas bypass pipe is connected between the upstream side and the downstream side of the apparatus, and the bypass is provided by a gas switching valve. It is possible to use a method of regenerating the collecting plate while flowing the exhaust gas through the pipeline.

[0015] In the apparatus of the present invention, the inner wall of the apparatus main body of the exhaust gas electric processing apparatus can also be used as the particulate matter collection surface.

The invention's effect

The electric processing method and apparatus for exhaust gas of a diesel engine of the present invention can remove PM in exhaust gas of a diesel engine with a high purification rate, and is combined with an oxidation catalyst and a NOx reduction catalyst. It is a harmful gas component in the exhaust gas. HC, C0, N0x can also be removed with a high purification rate. In addition, PM can be stably removed at a high purification rate over a long period of time, and excellent effects such as achieving substantially maintenance-free required for automobile parts can be achieved.

Needless to say, the present invention is effective for purifying various exhaust gases such as exhaust gas purification not only for diesel engines but also for direct injection type gasoline engines.

BEST MODE FOR CARRYING OUT THE INVENTION

[0017] Fig. 1 is a schematic diagram showing a first embodiment of an exhaust gas electrical processing apparatus for a diesel engine according to the present invention, and Fig. 2 is an electrode needle and a seal of a discharge electrode in the first embodiment apparatus. FIG. 3 is a schematic diagram showing another embodiment of the seal gas pipe in the first embodiment apparatus, and FIG. 4 is another implementation of the seal gas pipe in the first embodiment apparatus. Schematic diagram showing an example, FIG. 5 is a schematic explanatory diagram showing a PM collection plate in the first embodiment apparatus same as above, FIG. 6 is an explanatory diagram of a through hole of the PM collection plate in the first embodiment apparatus same as the above, (A) is an explanatory diagram showing the positions and diameters of the through holes of the PM collection plate, (b) is a cross-sectional view taken along the line AA of (a), and FIG. 7 is another PM in the first embodiment apparatus. FIG. 8 is a schematic view showing a collecting plate, (a) is a front view, (b) is a side view, and FIG. 8 is a diagram of an electric processing apparatus for diesel engine exhaust gas according to the present invention. FIG. 9 is a schematic cross-sectional view showing an enlarged main part of the second embodiment apparatus, and FIG. 10 is a first view of an electric processing apparatus for diesel engine exhaust gas according to the present invention. Fig. 11 is a schematic diagram showing an example of a means for removing PM oxidation of a collecting plate in the apparatus of the present invention. Fig. 12 is a schematic diagram showing an example of a combination of the apparatus of the present invention and a catalyst. FIG. 13 is a schematic view showing another embodiment of the combination of the device of the present invention and a catalyst, and FIG. 14 is a diagram of a _fourth embodiment of an electric processing device for diesel engine exhaust gas according to the present invention (with a cyclone dust collector). 15 is an enlarged schematic perspective view showing the collecting plate in the fourth embodiment apparatus shown in FIG. 14, and FIGS. 16 and 17 are views of the cyclone dust collector in the fourth embodiment apparatus shown in FIG. Fig. 16 shows an example of particle aggregation and coarsening means installed in the previous stage. Fig. 17 is a schematic perspective view showing a particle aggregation tube having a cam structure, Fig. 17 is a schematic perspective view showing a particle aggregation plate formed by arranging a plurality of punching metals, and Fig. 18 is a diagram showing a method for regenerating the collection plate of the apparatus of the present invention. It is the schematic which shows one Example.

[0018] As shown in FIG. 1, the exhaust gas electrical processing apparatus of the present invention is provided upstream of the exhaust gas passage 1. It consists of a corona discharge part 2-1 and a charging part 2-2 for charging the corona-discharged electrons 10 to the particulate matter S mainly composed of carbon in the exhaust gas G 1 in the main body wall 11 provided on the side The discharge charging unit 2 is provided, and the collector plate 3 for collecting the charged particulate matter S is arranged in the exhaust gas passage 1 in the main body wall 1 1 1 (two-stage type). The electrode needle 4 constituting the discharge electrode is arranged in the exhaust gas passage 1 through the seal gas pipe 5 made of a ceramic such as alumina and an insulating material such as heat-resistant glass toward the downstream of the exhaust gas flow. The section protrudes from the opening end of the seal gas pipe 5 by a predetermined length and is wired so that a direct high voltage of several tens of thousands of volts is applied from the external high-voltage power supply 6. The electrode needle 4 is made of a conductive material such as stainless steel or cemented carbide. Also, in order to promote the charging of the corona electrons 10, an exhaust gas guide pipe 7 is projected inside the main body wall 1 _ 1 provided in the middle of the exhaust gas passage 1, and the exhaust gas G1 is near the tip of the electrode needle 4. To flow. Further, the relationship between the inner diameter φ 1 of the main body wall 1 _ 1 and the inner diameter φ 2 of the outlet of the exhaust gas guide pipe 7 is not particularly limited, but is preferably about φ 2 / φ 1 <0.5. . Furthermore, in order to collect particulate matter S more effectively, the relationship between the distance La between the tip of the electrode needle 4 and the collection plate 3 and the distance Lb between the tip of the electrode needle 4 and the body wall is expressed as La. <Lb is preferred. The inner wall of the main body wall 11 1 is preferably covered with an insulator 11 such as ceramic in order to avoid thermal effects as much as possible. However, in the apparatus of the present invention, the inner wall surface of the main body wall 11 is also made of the particulate material S. It may be used as a collection surface. Alternatively, a collection plate 71-1 shown in FIG. 15 to be described later may be attached to the inner wall surface of the main body wall 1-1 to form a collection surface.

The direction of the seal gas G2 outlet of the seal gas pipe 5 is directed downstream of the exhaust gas G1 flow in order to prevent the electrode needle 4 from being contaminated. The flow velocity Qs of the seal gas G2 flowing in the seal gas pipe 5 (Fig. 2) is as long as the ratio (Qs / Qo) to the average flow velocity Qo of the exhaust gas G1 flowing outside the seal gas pipe 5 is 0.15 or more. The exhaust gas G1 can be prevented from getting inside the seal gas pipe 5. As the sealing gas, an insulating gas such as air is used.

[0020] The protruding length L of the electrode needle 4 from the tip of the seal gas pipe 5 (Fig. 2) is within the potential core Pc of the seal gas flow in the seal gas pipe 5 in consideration of electrode needle fouling. Position. Practical protrusion length L is 20-70mm. The potential core Pc will be briefly described. When seal gas (fluid) is ejected from the seal gas pipe 5, the seal gas pipe A uniform conical flow field is created at the outlet with the same flow velocity and gas components as in the inside of the nozzle. This area is called the potential core. The length of this potential core Pc region is usually about 5 times the inner diameter D of the seal gas pipe 5. The inner diameter D of the seal gas pipe 5 should be selected so that it does not spark from the electrode needle 4 to the PM adhering to the outer peripheral surface of the pipe at the outlet of the pipe. For a voltage of several tens of thousands of volts, the practical inner diameter D should be about 15 to 40 mm.

[0021] Furthermore, when the electrode needle 4 is subjected to corona discharge for a long time while being bare, the tip of the electrode needle 4_1 reacts with nitrogen in the atmosphere to generate nitrate, and the discharge characteristics deteriorate. In order to achieve long-term maintenance-free operation, it is necessary to apply a coating to prevent corrosion. As the coating material, a material having electrical insulation and corrosion resistance, for example, quartz glass, alumina, ceramic and the like is suitable. If the coating thickness is too thick, the electric field strength at the outer surface of the coating will be less than the corona discharge starting electric field strength Ec, so there is an appropriate thickness that depends on the electrode shape, DC voltage applied to the electrode needle, and exhaust gas conditions. However, practically, a thickness of about 0.:! To 0.5 mm is sufficient. The thickness of the portion other than the tip of the electrode needle may be thick without any particular restrictions.

[0022] The shape of the electrode that generates the corona discharge is not specified as long as it is an unequal electric field. For example, it may have a structure (not shown) in which a rod-shaped electrode tip is provided with a small sphere or a short electrode.

[0023] In the apparatus of the present invention, the measures shown in Figs. 3 and 4 are taken as means for further stabilizing the flow of the seal gas at the outlet of the seal gas pipe 5.

In other words, the measure shown in FIG. 3 is that a rectifying member 5-1 is arranged in the seal gas pipe 5, and for example, a plate-like member or a honeycomb-like member is used as the rectifying member 5-1. The rectifying member 5_1 may not be necessarily provided over the entire length of the seal gas pipe 5, but may be provided only in a portion where the gas flow direction changes, such as a bent portion of the seal gas pipe 5. By the action of this rectifying plate 5-1, the seal gas flow at the outlet of the seal gas pipe 5 becomes more stable, and an extremely stable potential core Pc is formed at the outlet of the seal gas pipe 5.

In addition, the countermeasure shown in FIG. 4 is to provide a gas flow in the seal gas pipe 5 by providing a dummy pipe part 5 _ 2 protruding to the upstream side of the exhaust gas passage 1 at the bent part of the seal gas pipe 5. The stabilization of is a powerful one. Here, the conditions for stabilizing the seal gas flow are as follows. As a result of the experiment, when the inside diameter of the seal gas pipe 5 is D, the length L2 of the dummy pipe part 5-2 of the seal gas pipe 5 part and the length L1 from the dummy pipe part to the tip part are respectively expressed as L1 / It has been found that D> 1.5 and L2 / D> 0.5 should be set. The inner diameter di of the dummy pipe section 5-2 can be larger or smaller than the inner diameter D of the seal gas pipe 5. Due to the action of this dummy pipe section 5-2, the seal gas flow at the outlet of the seal gas pipe 5 is stable, and it is extremely stable at the outlet section of the seal gas pipe 5 as with the seal gas pipe provided with the rectifying plate 5-1. A potential core Pc is formed. The reason why the seal gas flow is stabilized by providing the dummy gas pipe 5-2 in the seal gas pipe 5 is that a so-called buffer effect that attenuates pressure fluctuations in the cross section of the seal gas pipe due to bending of the seal gas flow occurs. It is thought that it is from. The reason for setting L1 / D> 1.5 and L2 / D> 0.5 is that if L1 / D is less than 1.5, the bent effect of the seal gas flow will not disappear, while L2 / D This is because if the value is less than 0.5, a sufficient buffer effect cannot be obtained. The upstream end face of the dummy tube portion 5-2 is not limited to a flat shape, and may be a semicircular shape or an elliptical shape that bulges upstream.

[0025] On the other hand, when the engine is stopped, the sealing gas is also stopped. It is desirable that the sealing gas is stopped after a while after the engine stops. This is because if the engine and seal gas are stopped simultaneously, there is a risk S that exhaust gas remaining in the exhaust gas pipe and collection device may enter the seal gas pipe 5 and contaminate the inside of the seal gas pipe and the electrode needle 4 . Further, it is desirable that the direction of the pipe when penetrating the seal gas pipe 5 through the main body of the collecting device is made to penetrate from the upper part to the lower part. The reason for this is to cause zero when exhaust gas is condensed to flow out to the seal gas pipe outlet side.

[0026] In the apparatus of the present invention, the collection plate 3 arranged on the downstream side of the electrode needle 4 is arranged so that the collection surface is perpendicular to the flow of exhaust gas, and the DC voltage of the electrode needle 4 and the collection are collected. This is a type that collects the PM8 charged by the discharge charging unit 2 by the Coulomb force by generating an electric field with the collector plate, and the punching metal type collector plates 3a and 3b shown in Figs. Fig. 7 shows three types of slit-type collecting plate 3c. That is, the punching metal type collecting plates 3a and 3b shown in FIGS. 5 and 6 each have a structure in which a large number of through holes 3a_l and 3b_l are provided in a single plate, and the collecting plate 3b shown in FIG. Has a structure in which a protruding flange (burring wall) 3b_2 is provided around the through hole 3b_l. When the protruding flange 3b_ 2 is provided, The vortex and stagnation are generated in the gas flow, and the collection efficiency of charged PM8 is improved. The height h of the projection flange 3b-2 may be about 0.:! In addition, the slit-type collecting plate 3c shown in Fig. 7 is provided with a large number of slits 3c-1 on a single plate member, and the back surface (the back side of the PM adhering surface) has heat removal during heating of the collecting plate. In order to prevent this, it has a structure in which a heat insulating material 3c_ 2 such as ceramic is pasted or a heat insulating paint is applied. The slit-type collecting plate 3c may be configured by using a plurality of strip-shaped plate members.

[0027] In the case of the punching metal type collecting plates 3a and 3b shown in Figs. 5 and 6, if the opening area of the through hole 3a_ l is S and the number of holes is N, the total area of the opening is NS Thus, if the collection area real front area is SO, the hole area ratio can be defined as the total opening area NSZ collection area real front area SO. In the case of the slit-type collecting plate 3c, as in the case of the punching metal-type collecting plate 3a, the aperture ratio can be defined as the total opening area NS of the slit / the real front area S0 of the collecting portion. . The hole area ratio is 3 to 20% for both the punching metal type collecting plate and the slit type collecting plate. The reason is that when the open area ratio is less than 3%, the amount of collected PM8 is high, but the pressure loss becomes large.On the other hand, when it exceeds 20%, the amount of collected PM8 cannot be obtained sufficiently. .

[0028] In addition, the average flow velocity of the exhaust gas G1 flowing through the collection unit is preferably slower from the viewpoint of collection efficiency, but practically, the actual front area SO of the collection unit is the amount before the exhaust gas treatment device. It is desirable to have a cross-sectional area that is at least 1.5 times the cross-sectional area of the exhaust gas introduction pipe and that the average flow velocity of the exhaust gas G1 flowing through the collection section is 20 m / sec.

[0029] The material of the collection plates 3a, 3b, 3c is not particularly limited, but is a ferritic stainless steel plate, austenitic stainless steel plate, or a high alloy heat generator material excellent in heat resistance and corrosion resistance. A metal plate such as nickel chrome can be used. The collecting plate can be covered with a washcoat layer to carry a catalyst.

[0030] It should be noted that the front shape of the collection plate 3 is not particularly limited as long as the exhaust gas flows without resistance, but the shape is round, square, other shapes, or the cross-sectional shape of the main body. Can be decided.

In the apparatus shown in FIG. 1, when a direct high voltage of several tens of thousands of volts is applied to the electrode needle 4 from an external high-voltage power supply device 6, a corona discharge phenomenon occurs at the tip of the electrode needle and corona electrons 10 are released. Is issued. PM8 in the exhaust gas Gl flowing in the space of the discharge charging unit 2 is charged by the corona electrons 10. The DC voltage applied to the electrode needle 4 is applied so that the electric field strength near the electrode tip is higher than the corona starting electric field strength. The set value of the DC voltage depends on the exhaust gas conditions (flow rate, PM content, temperature, etc.), but about 20 to 70 Kv is sufficient for practical use.

Next, a second embodiment of the present invention will be described with reference to FIGS. 8 and 9. This apparatus has a collecting portion 23 having a multilayer plate structure, and the structure thereof is an electrode plate holding rod 23. — A number of electrode plates 23-2 attached to 1 and grounded (not shown) collecting plates 23-3 arranged alternately with the electrode plates 23-2. 2 and the collection plate 23-3 are electrically insulated, and each plate surface is arranged parallel to the exhaust gas flow. The collecting part of this multilayer plate structure generates an electric field between the electrode plate 23-2 and the collector plate 23_3 to which the deflection voltage is applied from the high-voltage power supply device 26 via the electrode plate holding rod 23-1. This is a method of collecting the charged Ρ Μ8 that is generated and collected on the collection plate 23-3 by Coulomb force. When the gap between the electrode plate 23-2 and the collector plate 23-3 is small, the trapping efficiency is improved if it is narrow, but in practice it is preferably about! The deflection voltage is set to a voltage equal to or lower than the spark voltage depending on the gap L, exhaust gas atmosphere, etc. between the electrode plate 23-2 and the collection plate 23-3. The electric field strength (deflection voltage / gap L) between the electrode plate 2 3-2 and the collection plate 23-3 is practically about 250 to 100 OKv / m. Therefore, the deflection voltage is about 0.8 to 5 Kv. It's okay.

[0033] Insulation of the electrode plate holding rod 23-1 is basically covered with quartz glass, alumina, ceramic, etc. having electrical insulation and corrosion resistance, as in the case of the insulation of the electrode needle 4 described above. The voltage supply to the electrode plate 23-2 is performed from the high voltage power supply device 26 through the conductive wire and the electrode plate holding rod 23-1, but the main body wall of the exhaust gas treatment device of the electrode plate holding rod 23-1 is used. 1 Electrical insulation at the fixed part to 1 is important. The electrode plate holding rod 23_1 in the fixed portion of the main body wall 1_1 is disposed in a holding rod seal tube 9 made of an electrical insulator such as alumina or ceramic, and has an insulating seal gas G2 such as air. Shed. The flow rate Qs of the seal gas G2 flowing in the holding rod seal tube 9 is set to a ratio (Qs / Qo) of 0.15 or more to the average flow velocity Qo of the exhaust gas G1 outside the holding rod seal tube 9, and the holding rod seal Prevent the exhaust gas G1 from entering the pipe 9. In addition, the gap (interval) C between the inner surface of the holding rod seal tube 9 and the electrode plate holding rod 23-1 does not spark to the PM adhering to the vicinity of the opening of the main body wall of the holding rod seal tube 9. In the case where the deflection voltage is a voltage of several thousand volts by selecting such an inner diameter, a practical range of about 3 to 1 Omm is preferable.

The cross-sectional area of the collecting part of the multilayer plate structure in the second embodiment apparatus shown in FIGS. 8 and 9 is set by the average flow velocity Qo of the exhaust gas G1 flowing through the collecting part. The average flow velocity Qo of the exhaust gas G1 that flows through the collection section is preferably slower from the viewpoint of collection efficiency, but practically 1.5 times or more the cross-sectional area of the exhaust gas introduction pipe before the exhaust gas treatment device Therefore, it is desirable that the cross-sectional area be such that the average flow velocity Qo of the exhaust gas G1 flowing through the collection section is 20 m / sec or less.

[0035] Further, the material of the electrode plate 23-2 and the collection plate 23-3 of the apparatus of the second embodiment is similar to the collection plates 3a, 3b, 3c, and is a ferritic stainless steel plate having excellent heat resistance and corrosion resistance. It is desirable to use an austenitic stainless steel plate or a metal plate such as nickel-chromium, which is a high alloy heating element material, and the collection plate 23-3 that is coated with a washcoat layer and carries a catalyst. .

[0036] The apparatus of the third embodiment having the multilayer plate structure collection section 33 shown in Fig. 10 is configured so that the collection plate 33 1 for collecting PM8 in the exhaust gas G1 is formed in a multilayer shape and substantially in the exhaust gas flow. The collecting part is arranged in parallel to form the collecting part, and the plate surface of the collecting plate 33 1 is substantially flat, and the whole collecting part is joined to the main body wall 11 1 to apply a voltage. Since the electrode plate does not move, the entire collection part is grounded through the main body wall. In this type of PM collection mechanism, repulsive force works between PMs charged to the same polarity in the discharge charging unit 2, so that each charged PM 8 moves in the direction of the collection plate 331 and is collected. Further, the gap Lc between the collecting plates 33 can be narrowed because there is no electrode plate for applying a voltage and no spark occurs between the collecting plates 331, and the total collecting area can be increased. it can. Further, the gap Lc between the collecting plates 331 is practically about 0.5 to 5 mm. However, since this type of collecting part has no electric field between the electrode plate and the collecting plate as shown in FIG. 8, the collection efficiency per unit area is lowered, but the total collecting area is reduced. It can be compensated by an increase.

[0037] If the collecting plates 33 in the third embodiment apparatus have the same apparatus volume, the collecting area is the same as the electrode plates 23-2 and the collecting plates 23-3 of the second embodiment apparatus shown in FIG. A honeycomb structure that can be taken larger than the collecting part of the multilayer plate structure consisting of the above is advantageous in terms of collection efficiency. The average flow velocity Qo of the exhaust gas G1 flowing through the collection part consisting of this collection plate 33-1 is also As in the second embodiment, the average flow velocity Qo of the exhaust gas G1 that is 1.5 times or more the cross-sectional area of the exhaust gas introduction pipe before the exhaust gas treatment device and flows through the collection part is practically 20 m / se. A cross-sectional area that is less than or equal to c is desirable.

[0038] Further, the material of the collection plate 33-1 of the apparatus of the third embodiment is also a metal plate such as a fluorescent stainless steel plate and an austenitic stainless steel plate that is excellent in corrosion resistance, as described above. Further, the collecting plate 33-1 can be coated with a washcoat layer and loaded with a catalyst.

[0039] In each of the exhaust gas treatment apparatuses of the present invention described above, the charged PM8 once collected on the collection plate cannot fall off due to gravity or the fluid force of the gas flow. This is a characteristic of adhesion of fine particles. For particles with a particle size of 30 zm or less, the adhesion force by van 'Del' Warska increases even with gravity, and the ratio is said to be harmful to the human body. As a result, PM8 collected by running vibrations will not fall off.

[0040] Further, since the collection part of each exhaust gas treatment device has a structure with extremely small pressure loss, even if PM8 is deposited on the collection plate, there is almost no trouble with pressure loss. Therefore, under normal operating conditions, PM8 is naturally oxidized and removed if the exhaust gas temperature becomes high due to high-speed operation or high-load operation. However, when PM8 cannot be oxidized and removed spontaneously, such as when there is a long traffic jam in an urban area, PM8 deposited on the collection plate can be forcibly removed by electric heating.

FIG. 11 shows an example of the PM oxidation removal means of the collecting plate in the first embodiment of the present invention. As a material for the collecting plate 3, ferritic stainless steel and austenitic stainless steel having excellent heat resistance and corrosion resistance are shown. A thin plate made of steel or high alloy heating element material such as nickel chrome is used, and the collecting plate 3 is used as a heater. The means is that a switching switch 40 is installed at the end of the holding rod 3-1 of the collecting plate 3, and when the collecting plate 3 is electrically heated, it is connected to the terminal 40 a on the heating power supply 41 side, When collecting PM, it is possible to use a method of connecting to the ground side terminal 40b. The electric power required for this electric heating is as small as: ~ 4KW, so a battery mounted on the vehicle can be used as the heating power source. PM8 collected on the collection plate 3 is removed by oxidation at a temperature of about 550 ° C without generating a flame. Note that In order to avoid the necessary temperature rise, it is desirable to install a temperature measuring device (not shown) such as a thermocouple on the collection plate 3 to control the temperature during electric heating.

[0041] Next, an embodiment of the combination of the device of the present invention and a catalyst will be described with reference to Figs.

Here, the case where the apparatus of the first embodiment shown in FIG. 1 is adopted as the apparatus of the present invention will be described as an example.

Hazardous components in exhaust gas from diesel engines are classified into four types: soot (PM), hydrocarbons (HC), carbon monoxide (CO), and nitrogen oxides (Nx). Depending on the performance and operating conditions of the diesel engine, it may be sufficient to remove only PM. In that case, the purpose of exhaust gas purification can be achieved with only the exhaust gas electric treatment device of the present invention. However, when the exhaust gas electric processing apparatus of the present invention is combined with each catalyst, harmful components other than the PM in the exhaust gas can be more efficiently removed.

FIG. 12 shows an example of a combination of the apparatus of the present invention and a catalyst. For example, an oxidation catalytic converter 52 is installed on the upstream side (previous stage) of the exhaust gas electric processing apparatus 51 of the present invention. (HC) and carbon monoxide (CO) are oxidized to water (H〇) and carbon dioxide (CO

twenty two

The PM8 collected on the collection plate 3 of the exhaust gas electric processing device 51 is oxidized and removed by electric heating or when the exhaust gas temperature becomes high during high-speed operation, etc. Is done. In this case, nitrogen oxide (Nx) does not change significantly after passing through the purification device.

In addition, when using the collection part of an above-mentioned multilayer board structure as a collection part of the electric processing apparatus for exhaust gas of this invention instead of a single layer board structure, exhaust gas and a collection board contact. Since the surface area can be made larger than that of the collection part of the single-layer plate structure, it is advantageous for supporting the catalyst, and at least one of an oxidation catalyst and a three-way catalyst can be supported on the collection plate. As the oxidation catalyst and the three-way catalyst, at least one of platinum (Pt), palladium (Pb), rhodium (Rh), or a combination thereof is used. In order to improve the catalyst performance, it is desirable to add a promoter such as cerium (Ce) oxide.

Further, the combination example shown in FIG. 13 is the downstream side of the exhaust gas electric processing apparatus 51 of the present invention.

In the (second stage), Nx reduction catalytic converter 53 and oxidation catalytic converter 52 or a three-way catalytic converter (not shown) are installed, and further upstream of the exhaust gas electric processing device 51. The N0x reducing agent addition device 54 corresponding to the type of N0x reduction catalyst of the N0x reduction catalytic converter 53 is arranged on the side, and the addition device 54 uses the N0x reducing agent fuel and other Hydrocarbon and urea water can be appropriately added to the exhaust gas.

In the combination example of the above configuration, PM8 collected on the collection plate 3 of the exhaust gas electric processing device 51 is oxidized when the exhaust gas temperature becomes high due to oxidation removal or high speed operation by electric heating. Ox is removed by oxidation, and Nx is reduced and purified to N and O by the Nx reduction catalyst of NOx reduction catalytic converter 53, and further by the oxidation catalyst of oxidation catalytic converter 52.

twenty two

HC and CO are oxidized and purified to H 2 O and CO to remove all harmful components in the exhaust gas.

twenty two

Left.

As the NOx reduction catalyst, Cu-SAPO-34 (silicon aluminophosphate), Cu_ZMS_5 (copper ion exchange zeolite) or the like is used. Further, as the NOx catalyst, it is possible to use a known urea water as a reducing agent, a NOx reduction catalyst or a NOx occlusion reduction catalyst.

[0043] According to the first to third embodiments of the present invention described above, PM in the exhaust gas of the diesel engine can be effectively collected on the collection plate. Depending on the case, the electrical resistivity p may be low, and in such a case, the above collecting plate may not be able to cope with it sufficiently. Therefore, according to the present invention, a cyclone dust collector is attached after the electrical processing apparatus for exhaust gas.

Diesel engine exhaust gases have a PM electrical resistivity p that varies significantly depending on operating conditions, etc., and some PM has a high electrical resistivity p and some PM has a low electrical resistivity p. Generally a high temperature combustion during high-speed operation electric resistance rate _p tends to decrease the electrical resistivity p is large instrument also low-temperature combustion. Therefore, as a means for removing PM in the exhaust gas of a diesel engine, it is necessary to have a performance capable of collecting PM with low electrical resistivity p, which is not only PM with high electrical resistivity p, but also with high efficiency. Therefore, the present invention provides an exhaust gas for a diesel engine that can sufficiently cope with a high, low or low electrical resistivity P by attaching a cyclone dust collector to the subsequent stage of the exhaust gas electrical processing device. We propose an electrical processing device.

The device of the fourth embodiment shown in FIG. 14 is sufficient for both cases where the electrical resistivity p is high and low. This is an example of a diesel engine exhaust gas electrical treatment device that can handle the above, and a configuration in which a cyclone dust collector 62 is arranged downstream of the exhaust gas electrical treatment device 61 having substantially the same configuration as described above. is there.

Here, the collection plate 71_1 in the exhaust gas electric processing device 61 is a base plate 71- consisting of a single plate having no openings such as holes on the collection surface, as shown in an enlarged view in FIG. la and the grid-like fins 71 _ lb provided on the base plate 71 _ la collecting surface side, and the collecting plate 71-1 is a main body wall 61-1 of the exhaust gas electric processing device 61. It is arranged at an appropriate interval so as to form a gap 61-2 for allowing the exhaust gas to flow between it and the inner wall. The size of the gap 61-2 essentially does not affect the dust collection efficiency, so it can be determined in consideration of pressure loss. The reason why the grid-like fins 71-lb are provided on the collecting plate 71-1 is to efficiently collect the charged PM on the base plate 71_la by generating a stagnation effect on the gas flow.

The base plate 71-la and the lattice fins 71-lb of the collecting plate 71-1 are made of a conductive material such as metal because the base plate 71-la is grounded. 71- lb is an insulating material such as ceramics, considering the efficiency of PM collection and diving agglomeration (a phenomenon in which particles collide and coarsen in the process of repeated adhesion and scattering on the base plate). Is preferred. That is, when the grid fin 71-lb is made of metal, the electric force lines are concentrated on the tip of the grid fin 71-lb near the tip of the electrode needle 4, so that the charged PM is in the grid fin 71-lb. Since the gas flows toward the tip and the gas flow is fast at that part, PM is difficult to reach the base plate 71-la and is not easily collected, but is likely to scatter and flow backward. Because the efficiency is bad and the efficiency of the gathering agglomeration also gets worse.

is there.

In addition, in the main body of the exhaust gas electric processing device 61, a plate 61-3 with a guide hole is arranged upstream to promote the flow of exhaust gas and charging, and the collecting plate 71-1 and the collecting plate 71 — A plate 61_3 with a guide hole for promoting PM flow and collection and a field plate 61-4 for the purpose of applying an electric field may be installed between 1 and 1, respectively. In that case, a high voltage is supplied to the electric field plate 61-4 from a high-voltage power supply device (not shown), and the collecting plate 71-1 is grounded. [0045] In the case of the diesel engine exhaust gas electroprocessing device shown in Figs. 14 and 15, the charged PM is collected on the collecting plate 71-1 composed of the base plate 71-la and the lattice fins 71-lb. At this time, among the charged PMs that have reached the base plate 71-la, PM having a high electrical resistivity p is collected and deposited as it is on the base plate 71_la, while PM having a low electrical resistivity p is It is coarsened by the gathering phenomenon and collected on the base plate 71_la. When the amount of PM collected on the base plate 71_la subsequently increases beyond the limit amount, it will fall off naturally in a layered form, and the loose coarse PM will be removed by this electric treatment for exhaust gas. It is collected by a cyclone dust collector 62 arranged at the rear stage of the device 61. The PM collected in the cyclone dust collector 62 can be taken out and collected periodically, and a heater, etc. is installed in the cyclone dust collector.

It may burn during operation or when it is stopped.

[0046] As a particle aggregating and coarsening means installed in the subsequent stage of the exhaust gas electric processing device 61 and in the upstream of the cyclone dust collector 62, the particle-aggregating pipe 80 having a honeycomb structure shown in Fig. 16 has a gas flow velocity gradient. When exhaust gas is allowed to pass through the honeycomb-structured particle aggregation tube 80, collision aggregation is efficiently performed with the velocity gradient of the boundary layer generated at that time. In addition, the particle aggregating plate 90 shown in FIG. 17 utilizes agglomeration due to turbulent flow, and a plurality of punching metals 90-1 (three in this case) are arranged at a desired interval, and the exhaust gas is supplied to these three. When a particle agglomeration plate 90 made of a single piece of punching metal 90-1 is passed through, strong turbulence is generated and collision agglomeration is performed efficiently. As a method of causing the coagulation effect due to turbulent flow, instead of the punching metal, a wire mesh or a metal wire bundled in three dimensions is used.

It is also possible.

In the present invention, by using particle aggregation coarsening means such as the above-described honeycomb-structured particle aggregation tube 80 or particle aggregation plate 90, the PM particles exiting the exhaust gas electric processing device 61 are grown into larger particles. Therefore, it can be efficiently collected by the cyclone dust collector 62 in the latter stage.

[0047] On the other hand, FIG. 18 shows a method for regenerating the collection plates 3, 3a, 3b, 3c, 23-3, 33_1, 71_1 of the electric processing apparatus for exhaust gas of the present invention. As shown in the example, exhaust gas Between the upstream side and downstream side of the electrical processing equipment 51, 61 for industrial use, a bypass pipe 55 without an electrical processing equipment for exhaust gas is installed, and the switching valve V provided in the upstream exhaust gas pipe is used. The method of collecting and regenerating PM by controlling the flow of exhaust gas can be used. That is, when PM8 is collected by the exhaust gas electric processing devices 51 and 61, the A route is used by the switching valve V, and when the collection plate is regenerated, the switching valve V is used as a bypass pipe. Use Route 55 B route. In addition, because there is no electrical processing equipment for exhaust gas in the bypass route 55 of route B, the regeneration time of the force collecting plate that is discharged without collecting PM when using the route is:! ~ 2 minutes Because it is a short time, there is almost no actual damage such as air pollution.

[0048] In addition to the regeneration method shown in FIG. 18, although not shown, for example, an exhaust gas electric processing device 51 is also installed in the bypass route 55 of the B route to alternately collect and regenerate. There are two methods, for example, or two exhaust gas processing units 51 installed in series, and alternately collecting and regenerating, of which two exhaust gas processing units 51 are installed in series. This method is safer for preventing air pollution because the collection efficiency of PM8 is increased, and even when one of the exhaust gas electrical treatment devices fails, the other device can collect them.

Industrial applicability

[0049] The exhaust gas electrical processing device for a diesel engine of the present invention can reliably collect and oxidize and remove PM in the exhaust gas. Therefore, by combining various catalyst technologies, harmful gases other than PM can be obtained. Components can also be removed efficiently, and PM particles can be collected more effectively when combined with a cyclone dust collector and particle agglomeration / roughening means. It can also be applied to purification treatment of various exhaust gases containing various exhaust gases and harmful components, and contributes greatly to the prevention of air pollution pollution.

Brief Description of Drawings

FIG. 1 is a schematic view showing an apparatus of a first embodiment of an electric processing apparatus for exhaust gas of a diesel engine according to the present invention.

FIG. 2 is an explanatory view of the electrode needle of the discharge electrode and the tip of the seal tube in the first embodiment apparatus. 3] It is a schematic diagram showing another embodiment of the seal gas pipe in the first embodiment apparatus same as above.

4] A schematic view showing another embodiment of the seal gas pipe in the first embodiment apparatus.

FIG. 5 is a schematic explanatory view showing a PM collecting plate in the first embodiment apparatus.

6] An explanatory view of the through hole of the PM collection plate, (a) is an explanatory view showing the position and diameter of the through hole of the PM collection plate, and (b) is a cross section along the A_A line of (a). FIG.

7] A schematic diagram showing another PM collection plate in the first embodiment apparatus, wherein (a) is a front view and (b) is a side view.

FIG. 8 is a schematic diagram showing an apparatus of a second embodiment of the electric processing apparatus for exhaust gas of a diesel engine according to the present invention.

FIG. 9 is an enlarged schematic cross-sectional view showing the main part of the second embodiment apparatus.

FIG. 10 is a schematic diagram showing an apparatus of a third embodiment of the electric processing apparatus for exhaust gas of a diesel engine according to the present invention.

11] It is a schematic explanatory view showing an example of PM oxidation removing means of the collection plate in the device of the present invention.

FIG. 12 is a schematic view showing an example of the combination of the device of the present invention and a catalyst.

13] Similarly, it is a schematic view showing another embodiment of the combination of the device of the present invention and a catalyst.

FIG. 14 is a schematic view showing the apparatus of the fourth embodiment (with a dust collector with a cyclone) of an electric processing apparatus for exhaust gas of a diesel engine according to the present invention.

15] FIG. 15 is a schematic perspective view showing the collection plate in the fourth embodiment apparatus shown in FIG. 14 in an enlarged manner.

16] FIG. 16 is a schematic perspective view showing a honeycomb-structured particle aggregating tube as an example of particle aggregating and coarsening means installed in the front stage of the cyclone dust collector in the fourth embodiment apparatus shown in FIG. 17] FIG. 17 is a schematic perspective view showing a particle aggregating plate in which a plurality of punching metals are arranged at intervals in another example of the particle aggregating and coarsening means.

18] It is a schematic diagram showing an embodiment of the regeneration method of the collection plate of the device of the present invention.

19] An example of a conventional diesel engine exhaust PM collection device subject to the present invention It is a schematic explanatory drawing shown.

Explanation of symbols

1 Exhaust gas passage

1- 1, 61-1 Body wall

2 Discharge charging part

2-1 Corona discharge section

2-2 Charging part

3, 3a, 3b, 3c, 23-3, 33-1, 1, 71-1 Collection plate

4 electrode needle

5 Seal gas pipe

5-1 Rectification member

5-2 Dummy pipe

6 High voltage power supply

7 Exhaust gas guide pipe

8 PM

9 Holding rod seal tube

10 Corona Electronics

11 Insulator

23, 33 Collection part

23-1 Electrode plate holding rod

23-2 Electrode plate

0 changeover switch

0a, 40b terminals

1 Heating power supply

51, 61 Electric processing equipment for exhaust gas

2 Oxidation catalytic converter

3 NOx reduction catalytic converter 53

4 Addition equipment 55 Bypass line G1 Exhaust gas

G2 seal gas Pc potentiorecore V selector valve

Claims

The scope of the claims

[1] In the electric processing method for exhaust gas of a diesel engine, a discharge charging unit comprising a corona discharge unit and a charging unit is provided upstream of the exhaust gas passage, and the carbon in the exhaust gas is removed from the corona discharged electrons. An electric processing method for exhaust gas of a diesel engine, characterized in that the charged particulate matter is collected by a collecting portion disposed in the exhaust gas passage, with the particulate matter as a main body being charged.

[2] In an electric processing device for exhaust gas of a diesel engine, a corona discharge unit and a charging unit that charge corona discharge electrons upstream of the exhaust gas passage to particulate matter mainly composed of carbon in the exhaust gas. An electric processing apparatus for exhaust gas of a diesel engine, characterized in that a discharge charging unit comprising: a collecting unit for collecting the charged particulate matter is disposed in the exhaust gas passage.

[3] The diesel engine according to claim 2, wherein the discharge side tip of the electrode needle of the corona discharge part is arranged toward the downstream side of the exhaust gas flow, and corona electrons are discharged toward the downstream side. Electric processing equipment for exhaust gas.

[4] The electrode needle is inserted and arranged in a seal gas pipe made of an insulator.

4. An electric processing device for exhaust gas of a diesel engine according to 3.

5. The electric processing apparatus for exhaust gas of a diesel engine according to claim 4, wherein the seal gas pipe is made of alumina ceramic.

[6] The diesel engine exhaust gas electricity according to claim 4 or 5, wherein the protruding portion of the electrode needle from the end of the seal gas pipe is positioned in the potential core of the gas flow in the seal gas pipe. Type processing device.

7. The electric processing apparatus for exhaust gas of a diesel engine according to any one of claims 4 to 6, wherein the electrode needle is coated with a material having electrical insulation and corrosion resistance.

8. The electric processing apparatus for exhaust gas of a diesel engine according to claim 7, wherein quartz electrode, alumina, or ceramic is used as a coating material for the electrode needle.

9. The electric processing apparatus for exhaust gas of a diesel engine according to any one of claims 2 to 8, wherein the collection part has a single layer plate structure or a multilayer plate structure.

[10] The collection part is composed of a punching metal type collection plate or a slit type collection plate, and the opening ratio defined by the total area of the opening part / the front surface area of the collection part is 3 to 20 The electric processing device for exhaust gas of a diesel engine according to any one of claims 2 to 8, characterized in that the percentage is%.

[11] The structure according to any one of claims 2 to 8, wherein the collection part is configured by a base plate made of a single plate having no opening on the collection surface and a lattice-shaped fin provided on the collection surface side of the base plate. Power Diesel engine exhaust gas treatment system as described in item 4.

12. The electric power for exhaust gas of a diesel engine according to claim 9, wherein the electrode plate holding rod in the collecting portion fixing portion of the single layer plate structure or the multilayer plate structure is disposed in an insulating seal pipe. Type processing device.

[13] The electric processing device for exhaust gas of a diesel engine according to any one of claims 4 to 12, wherein a flow regulating member is disposed in whole or in part in the seal gas pipe.

14. The diesel engine exhaust gas electrical processing device according to claim 13, wherein the rectifying member is a plate or a honeycomb.

[15] A dummy tube portion is provided on the tube wall opposite to the tip side of the electrode needle of the seal gas tube in parallel with the exhaust gas flow direction. The electric processing apparatus for exhaust gas of the diesel engine as described.

[16] The seal gas pipe having the dummy pipe part has an inner diameter of the seal gas pipe as D, a length of the dummy pipe part of the seal gas pipe part as Ll, and a length from the dummy pipe part to the tip part as L2. L1

16. The electric processing apparatus for exhaust gas of a diesel engine according to claim 15, wherein the conditions /D>1.5 and L2 / D> 0.5 are satisfied.

[17] The exhaust gas electric processing device for diesel engines according to any one of [4] to [16], wherein the exhaust gas electric processing device and a catalyst are used in combination.

[18] The exhaust gas for an exhaust gas of a diesel engine according to any one of claims 2 to 17, wherein the exhaust gas electric processing device is provided with a cyclone dust collector in a subsequent stage. Electric processing equipment.

[19] The collection unit of the exhaust gas electric processing apparatus includes a base plate made of a single plate having no opening on the collection surface, and lattice-shaped fins provided on the collection surface side of the base plate. 19. The electric engine for exhaust gas of a diesel engine according to claim 18, characterized in that one or a plurality of collecting plates configured as described above are arranged so that a gap is formed between the inner wall of the apparatus body. Processing equipment.

[20] The exhaust of the diesel engine according to claim 18 or 19, wherein a particle aggregating and coarsening means is disposed in a subsequent stage of the exhaust gas electrical processing device and in front of the cyclone dust collector. Electric processing equipment for gas.

21. The diesel engine according to claim 19 or 20, wherein as the particle aggregation coarsening means, a particle aggregation tube having a honeycomb structure, or a particle aggregation plate configured by arranging a plurality of punching metals or wire meshes at intervals is used. Electric processing equipment for exhaust gas.

[22] The force according to any one of [2] to [21], wherein an inner wall of the apparatus main body of the electric processing apparatus for exhaust gas is also a collection surface or a collection section of the particulate matter. Electric processing equipment for diesel engine exhaust gas.

[23] As a method of regenerating the collection plate of the exhaust gas electric processing apparatus, an exhaust gas bypass pipe is connected between the upstream side and the downstream side of the apparatus, and a gas switching valve is connected to the bypass pipe. 23. The electric processing apparatus for exhaust gas of a diesel engine according to any one of claims 2 to 22, wherein a method of regenerating the collecting plate while flowing the exhaust gas is used.